I have done a bit of plastics welding before. Couple things, you need a GOOD plastics welder and you MUST have the same base plastics filler rod or it simply won't work.

I have welded 1/8" all the way up to schedule 80 HDPE. My repairs on the schedule 80 HDPE was for 6" high pressure irrigation line. that is spooled up. 5 years later the repairs are still holding water tight under several hundred PSI.

I suggest you contact the manufacturer of the light's housing and then source a good platics welder for rent. The one i used was $1500 unit and was not overly complicated but was exactly what was needed.

Best of luck.

Grant

 

I'm going to be going for a heat gun. Does it matter the quality? I'm only using it for this one project, then most likely never again.

 

what about this gun... http://www.ebay.com/itm/Porter-Cabl...-Heat-Gun-/300638529822?pt=LH_DefaultDomain_0&hash=item45ff73e91e#ht_991wt_1110

 

I'm thinking you could save yourself a lot of time and trouble.

Just take a 55gal drum.

Cut in half.

Pour in one can of charcoal starter.

Once the fire is started, throw in the light.

Think that will work about as well as what you're proposing.

 

Hey Jay he didn't say BBQ.......

FIXED IT!

 

Thanks, smartass. Im obviously going to use attachments with a heat gun, and not blow dry my headlight.

 

Hey PrimeTime,
Don't get so upset with responses that you "feel" are insulting. You come to a welding forum, a forum that is generally dedicated to METAL welding/repairs, & ask about plastics. Have you done any research on the "plastic welding forums"? I'm sure there are areas of info that may give you a much better level of comprehension as to the fusion of plastics. Just like steel, alum., copper, brass, etc., each has a suitable filler, heat requirement/process that will allow success. Plastic is the same as to chemical/structural parameters that have be met for weld integrity & fusion.

For your application, I would suggest this unit that may fill your needs & might be a handy tool to keep in your shop for any other future plastic needs you may encounter. Never know if/when a buddy may need/want a repair to some plastic auto/truck part & besides, you could make a few $$$ on the side of you'd learn to get really good with it. Wouldn't take long for the unit to pay itself off.... Just some mental fodder to contemplate.

Here's the link: http://www.harborfreight.com/weldin...elders/plastic-welding-kit-with-air-motor-and-temperature-adjustment-96712.html

Denny

Addendum: Here's a past thread you may find interesting: http://weldingweb.com/showthread.php?t=63007&highlight=plastic+welding

 

Here's the link: http://www.harborfreight.com/weldin...elders/plastic-welding-kit-with-air-motor-and-temperature-adjustment-96712.html

Ive actually spoke to a technician @ harbor freight earlier this week about this tool, but according to them, there isnt a speed welding attachment that will fit this. Does anyone know of an attachment that I can use to attach this to that harbor freight tool?

 

While a dedicated plastics welding machine uses heat, it is not a heat gun as you propose. The one I used was a Cadillac brand and was a variable heat adjusted unit. You used the filler rod WITH the machine by feeding it in the machine and to the part to be welded. As you heat, the fed rod comes out the speed as which you move.

My suggestion to you is either have someone do this for you or simply epoxy it because you are not going to get any decent results with your proposed plan.

Do it the right way or pay someone to do it the right way.

Grant

 

here is a very good source of information for you: http://urethanesupply.com/

 

I'd like to know what you plan to do?It does not have to be absolutely dry all new lights have vent tubes,so don't worry if you don't get it, the lights get hot and water purges.
Use a panel saw, air saw for fiberglass with thin blade or patiently with dremel and its cut off blades they are about .030 thick, then
II'd go to an adhesive, or do a lot of practice before you try, like a lot of novice welding, with plastic you cannot tell when plastic reaches welding temperature as their is no good indicators and it is hard to see what your welding and the final appearance is not usually well finished.This is why you don't see this often.
best

 

PrimeTime,

I bought one of the Harbor Freight Plastic welders and it works pretty good now that I have learned to use it properly. There is quite a learning curve to plastics I am finding. Now..............Once you determine the proper plastic filler rod to use, here is a slick trick I was taught by an engineer/mad scientist. Grab your Dremel or borrow one. Cut a piece of the plastic filler rod so there will be about 3/4" sticking out after it is inserted into the Dremel collet/chuck...........any more than this and you get a bad wobble. Scrape, sand, or grind any shiny coating from the area to be welded. Bevel the 2 pieces or crack at least half way through the thickness........the deeper the better. Clean the area with some rubbing alcohol. Turn the dremel on just a little less than full speed. touch the spinning rod to the joint and apply moderate pressure..........be patient. When you see the plastic forming around the rod it is melting. Go slow, and several thin layers usually work better than trying to fill it all at once. It helps to practice on scrap plastic until you understand how it is going to work............Plastic friction welding.

 

As pistolnoon mentioned, the finished bead is NOTHING like a weld bead. Further, the bead almost always sits very high on the base material. If the filler is thicker, it will be even MORE pronounced.

The big thing overall is getting the correct filler matched to the base material and a proper welder to apply.

 

I used a unit similar to this one, only the one I used was a Cadillac brand. I did some work for a Hot Rod shop years ago and in return, they let me borrow their plastics welder when I needed it. IIRC, they told me the unit was $1500 new. Looks like most of the decent and similar quality ones like the one I used are dirt cheap at $200-300! Leister has a decent line as mentioned.

http://www.professionalplastics.com/WEGENER-AUTOTHERM

Grant

On edit, here is an adapter that you are looking for. Not sure how well this whole set up would work as heat would start to dissipate.

http://www.ebay.com/itm/5MM-WELDING...-HOT-AIR-PLASTIC-WELDER-/160662838513?pt=LH_DefaultDomain_0&hash=item2568405cf1

 

I did a Z28 tail light and surgicly opened it up by heating an exacto knife red hot and gently cutting it open. With what you are trying to do, You may want to just use adhesive to glue it back together. You can heat a screwdriver and use it to tack the light shut and then they have awesome adhesives for thin plastics. Check Devcon. I have done a lot of plastic welding and I believe it lends itself better to ATV fenders and the like. Thin brittle plastics like you have are difficult to weld and make them look good. Get a scrap one of similar and practice 1st.